The technical field of the invention is that of prefilled, disposable needleless injection devices, operating with an energy source such as, for example, a gas generator and used for intradermal, subcutaneous and intramuscular injections of liquid active principle for therapeutic use in human or veterinary medicine.
The active principle consists of a more or less viscous liquid, a liquid mix, or a gel. The active principle may also be a solid in solution in a solvent suitable for injection, or consist of a powdery solid suspended at a certain concentration in an appropriate liquid. The particle size of the active principle must therefore be compatible with the diameter of the ducts to avoid blocking them.
Needleless injection devices comprising a reservoir of active principle already exist in tube form equipped with a flange and have been the subject of patents. For example, the patent application FR 2 853 837 may be cited, which relates to a needleless injection device comprising an injection nozzle and a tube intended to receive an active principle to be injected, said tube being fixed to said nozzle with the help of connecting means. The main technical feature of this injection device is that the tube containing the liquid active principle comprises a flange that will fit into fixed connecting means on said nozzle for joining said tube to said nozzle in a solid and reliable manner. The flange has a purely mechanical function which is that of a fixing piece.